And as for the pressure of the big day, with the eyes of the world on him, the Archbishop of Canterbury is taking it in his stride, instead focusing on the couple.

"It's their day. At the heart of it are two people who have fallen in love with each other who are committing their lives to each other with the most beautiful words and profound thoughts in the presence of God," he said.

Meghan Markle was spotted with a new piece of jewellery. (PA/AAP)

Following the secret service last Tuesday, the American actress was spotted with her fiance Prince Harry in Birmingham for an official visit.

It appears the bride-to-be has marked her baptism with a new piece of jewellery, after being spotted wearing a diamond cross bracelet she hasn't worn for previous royal outings.

According to People, the accessory, which she wore alongside another diamond band, is likely a nod to the bride-to-be's recent confirmation.

Markle, who was raised a Protestant, is not required to be Anglican in order to marry Prince Harry, 33.

A closer look at Markle's 'baptism bracelet'. (PA/AAP)

However, it’s believed she chose to embrace the faith in respect of Queen Elizabeth’s role as head of the Church of England.

The Daily Mail reports the 45-minute ceremony - held at the Chapel Royal in St James' Palace - was attended by 18 guests, including Markle's fiance Prince Harry and future parents-in-law Prince Charles and Camilla, Duchess of Cornwall.

While it was initially reported the 36-year-old's parents Thomas Markle and Doria Ragland would travel from Mexico and California to attend, they were reportedly absent.

Markle is said to have formed a "close bond" with the Archbishop of Canterbury, who has been teaching her about the Church's rites and sacraments in recent weeks.

Prince Harry and Meghan Markle will marry on May 19. (Getty)
Welby will also officiate the Royal Wedding at Windsor Castle on May 19.
The 62-year-old recently told reporters the fact Markle has previously been married was “not a problem” from the Church’s perspective.
"The Church of England has clear rules with dealing with that and we've dealt with that,” he said last month.

LISTEN: The key to making new habits stick, according to the Life Bites podcast. (Post continues.)

"We went through that as anyone would who will officiate at a wedding where someone has been separated and a partner is still living."

Markle's intention to be baptised as part of her wedding preparations was revealed by the Kensington Palace in November, when her engagement to Prince Harry was officially announced.
The Suits star isn’t the first royal bride-to-be to do so, either.

The Duchess of Cambridge was also confirmed ahead of her royal wedding. (AAP)

Kate Middleton was also confirmed in the Church of England before marrying Prince William in 2011, though she had already been baptised as a child.

Embracing a new faith isn't the only major change in store for Markle, who relocated to London from her base in Toronto ahead of her engagement.